Mr. Thomas Gray, writing from Brussels in November, 1821, suggests steam coaches on iron rails. In support of it, he stated that the journey to Edinburgh would be done in half the time taken by the mail coaches, and that the expense of laying the iron rails would be more than covered by the extra passengers that could be carried in the additional coaches which could be run. This also met with a cold reception, and no doubt appeared at the time to be simply speculative, yet the light of time compels us to take a different view, and to recognize in it the germs of a great invention. Mr. James Rondeen, of Lambeth, on June 3rd, 1823, submitted a scheme to convey the mails by engines consuming their own smoke, of four or six-horse power, which would cost from two hundred and fifty to three hundred pounds each, and impel a coach at the rate of from fifteen to twenty miles an hour. He estimated that there were two hundred and eighty coaches running daily from London and on the cross roads, the work of which, if his scheme was adopted, would be performed by eighty-two engines. This scheme was considered an extraordinary one, but the condition of its acceptance imposed by the inventor could not be complied with. I should gather from what is said here, that Mr. Rondeen's plan was of the nature of a traction engine to run upon the existing turnpike roads, and, if I am right, the Postmaster-General of that day had a better opinion of that mode of progression than of the system of rails. No doubt, several descriptions of traction engines were tried, but none succeeded, and I have heard of surveyors of turnpike roads laying such extra thick coverings of stone on the roads as to clog the engine wheels; but however this may be, experience has proved that they are not capable of much pace, however useful they may be found for slow traffic. A Mr. Knight, in January, 1822, suggested an elevated road or railway. The carriage was to be slung from the road on rails above, and two men, suspended in it at the bottom, would turn machinery to propel it along the groove or railway. After the idea had been talked over by Mr. Knight with the head of the mail coach department, the latter was satisfied that it would be of no use to the Post-office. A Mr. Elmes of Regent Street, in October, 1823, offered to convey the mails to any part of the United Kingdom at the rate of from fifteen to seventeen miles an hour, by means of a mechanical carriage, which could be worked by horses or not. He stated that his contrivance would reduce the cost of conveyance to about a quarter of that then incurred. It need hardly be said that this proposal was too indefinite to be entertained.